What is multiple myeloma? Multiple myeloma is a cancer of a white blood cell called a plasma cell. Normal plasma cells reside in the bone marrow and are responsible for producing antibodies to fight off infection. And if one of these plasma cells develops the right set of mutations and chromosome alterations, then it will unfortunately start to grow out of control and increasingly occupy the bone marrow. And when that happens, then we start to see some of the manifestations that we typically think of with multiple myeloma. The myeloma starts to overgrow the bone marrow. We see anemia. Those myeloma cells are sending signals to bone-breaking down cells to break down bone, so you start to see bone damage. You see the calcium leaching out of the bone leading to high levels of calcium in the bloodstream. And you know, even though these plasma cells are cancerous, they're still making antibody, and occasionally those antibodies, especially light chain antibodies, can deposit the kidney and cause kidney damage.
What Dr. Voorhees has just described is known as the CRAB criteria or symptoms of myeloma. Calcium builds up in the blood causing hypercalcemia or too much calcium. Renal or kidney disease can be caused by a buildup of antibodies produced by the cancerous myeloma cells. Anemia can develop as red blood cells get crowded out by those proliferating cells, and bone damage can develop from too much breaking down of the bone caused by the myeloma cells.
I think it's important for all patients to understand that while we don't necessarily view multiple myeloma as curable, at least for the majority of patients, I think that the therapy has become increasingly effective. The overwhelming majority of patients will respond to treatment, and particularly for those patients who have standard-risk disease, that initial remission can last many years.
So multiple myeloma is a cancer of plasma cells. So plasma cells are one type of white blood cell that helps our body fight infection. And why the plasma cell becomes cancerous, we don't quite understand, but we feel that there is probably some genetic component and significant environmental component that makes these plasma cells become abnormal. Now just the abnormality in the plasma cell by itself is not very uncommon, especially in the older patients. Almost five to six percent of patients over 70 might have an abnormal clone of plasma cells that makes a monoclonal protein, but the majority of the people it does not progress to myeloma. So we are still trying to also understand why some people turn to myeloma and some people don't.
What causes myeloma is difficult to narrow down. In terms of what we can do for the myeloma, there are a lot of different treatments that can keep the myeloma under control for a long period of time. We can't quite say that we can cure the myeloma, but we seem to be making steady progress to it.
HealthTree • June 3, 2020
